Traditionally, wheelchairs to mobility devices have been used to aid in the transportation of invalids. Government statistics now show that one in every two hundred people is confined to a wheelchair. The conventional wheelchair devices have experienced problems due to neck pain from looking upward, bowel and bladder problems from remaining in a persistent seating position and other general heath problems due to lack of circulation, etc. It has long been known to provide wheelchairs which are mechanized to the extent of being convertible from a sitting position to a standing position. However, wheelchairs of that type have generally not be suited for mobility, because powered propulsion equipment has created a risk factor, as well as providing a mobility device which cannot get close enough to countertops, nor can the wheelchair extend underneath the kick plates located in almost every kitchen or bathroom.
A study of the anthropometric average of all humans has led to a standard table height of about 29 inches. Whether a person is 7' tall, or 4'6", their fingertips generally are suspended about 29" above the ground. Furthermore, a standard reach has been adjusted for faucets and other such items, requiring a 4" indentation underneath sinks, known as kick plates. If the body of the invalid on a stand-up wheelchair as closed in the prior art is raised up from several inches to about 10" off the ground, the anthropometric average has been disturbed, and the fingertips of the person will not be able to reach the countertop. In addition, if the stand-up portion of the wheelchair does not fit underneath the kick plate next to kitchen and bathroom faucet and sinks, the invalid will generally not be able to reach the faucets and the backs of countertops of their non-invalid brethren. Therefore, it would be a great advantage to provide a stand-up wheelchair which would allow for the invalid to be in a standing position while also being able to be extremely close to the ground so as not to effect the anthropometric averages which are inherent in the body build and shape of the invalid.
Prior art mobility devices were inherently unstable because most of the weight would be placed on the front of the wheelchair when the patient or invalid was in the standing position, rendering the device unstable. It would also be of great advantage to provide a stand-up wheelchair, which would provide stability for the person operating the wheelchair, or for the invalid standing in the wheelchair.
Other stand-up wheelchairs have been manufactured which can stand the invalid in an upright position, but cannot get close enough to faucets and sinks, nor are they rotatable in a very small diameter, such as for example, to be able to rotate 180.degree. in a doorway. In addition, other chairs and stand-up wheelchairs must be at least 4" off ground over a 30" wheel base to clear a maximum of a 28.degree. incline such as are designed in handicap ramps. Without a platform that can raise and lower itself, the wheelchair or invalid mobility device would not be able to be usable on a handicap ramp while in a standing position. Again, the anthropometric averages of most human beings are between 28 to 32 inches. The designs of all standing household devices relate to these averages so that normally sized human beings are able to use countertops and drawers. If the human is in a standing up position, and they are in a stand-up wheelchair which places the entire body anywhere from 4 to 10 inches from the ground, and the invalid can't bend over, they would not be able to use normal work surfaces such as faucets, or to pick-up a screw driver from a work surface. In order to help invalids return to a normal working environment, they must be able to simulate normal mobility and height standards in order to be able to compete with their non-invalid counterparts. Every counter and cupboard has a 2 to 4 inch kick plate recessed area underneath which brings us closer to faucets etc. If the platform underneath the stand-up wheelchair keeps one approximately 4 inches away from the counter because it will not fit underneath the kick plate, combining that with removing the 2 to 4 inches under the kick plate, the invalid actually is an additional 7 inches away from a faucet. If the invalid cannot bend over in order to compensate for that additional distance which needs to be travelled, the invalid cannot touch nor reach the faucets or cupboards or other items. Average leg, arm and torso lengths of all human beings have determined the anthropometric average of 30" for a table height, and a 20" depth generally for countertop and kitchen and bathroom sinks. It is for these reasons that the prior art stand-up wheelchairs have not been able to function well within a home or a work place setting. Patents on prior art devices which will be discussed below can be readily seen to conflict with these requirements for simulated normal mobility of an invalid within a home or work place. Attempts to produce stand-up wheelchairs which are mobile have met with failure because platforms upon which the invalid stood did not allow for a lower clearance to the ground in order to maintain the anthropometric averages. Examples of previous attempts to solve these problems are described in the following patents. U.S. Pat. No. 3,907,051 issued Sept. 23, 1975 to Weant et al. discloses a stand-up wheelchair which includes a motor-operated means for raising and lowering a partially paralyzed person from a seated to a substantially standing position. Once the invalid is standing, it appears that stability would be compromised due to the large wheels and the fact that the platform does not apparently touch the ground.
U.S. Pat. No. 3,964,786 issued June 22, 1976 to Mashuda discloses a wheelchair in which the seat, back and leg portions are so articulated and separately actuable, by power means, under control of the occupant, as to enable the occupant to assume any of one of three positions, either sitting, standing or reclining. From the figures and description, it does not appear that the anthropometric averages would be maintained.
U.S. Pat. No. 4,119,164 issued Oct. 10, 1978 to Fogg, Jr. et al. discloses a wheelchair designed to enable an invalid to stand to perform useful work and to move about. However, again, it does not appear that a platform as shown in the figures and described in the description would maintain the anthropometric averages necessary for simulated normal movement.
U.S. Pat. No. 4,155,416 issued May 22, 1979 to Ausmus discloses an occupant-operated motorized vehicle for supporting paraplegics in a standing position for working with their hands. Again, the platform means upon which the invalid will stand appears to alter the height of the invalid, thereby changing the anthropometric averages.
U.S. Pat. No. 4,390,076 issued June 28, 1983 to Wier et al. discloses an integrated ambulator and wheelchair to enable a paraplegic to stand on the ambulator and be separated from the wheelchair for maneuvering in confined spaces Although the separate ambulator would be able to allow the invalid to move freely within a space, the platform attached thereto would change the anthropometric average.
U.S. Pat. No. 4,437,537 issued March 20, 1984 to Ausmus describes an occupant operated motor driven vehicle for supporting handicapped occupants adapted to be tilted forward by the occupant for retrieving articles lying on the vehicle's support surface, and to be restored to vertical operating position. The platform means does not appear to be integrated into any sort of wheelchair, nor does it appear to maintain anthropometric averages.
U.S. Pat. No. 4,456,086 issued June 26, 1984 to Wier et al. discloses an integrated wheelchair and ambulator which allows a paraplegic to stand, although it contains a platform which is undesirable in order to maintain anthropometric averages. Therefore, it is a primary object of the present invention to provide an invalid mobility device or stand-up wheelchair in accordance with the present invention which is capable of allowing an invalid to stand, while maintaining the anthropometric averages to allow the invalid to experience approximate normal motion and simulated normal activities and mobility but will allow routine functions to be performed like non-invalid counterparts.
It is yet another object of the present invention to provide an invalid mobility device which includes tripod stability for enhanced rotation capabilities to further aid in simulating normal motion and maneuver ability in tight quarters.